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Old 06-14-2018, 08:35 PM   #26
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Join Date: Jan 2011
Location: Stuart, Florida
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Re: '89 K1500 engine replacement help

Originally Posted by ChevyTech View Post
Wow, there it is. If you knew how much I looked for that before I asked..... We plan on working on it this weekend. Have a mechanical pump, just need to make a metal fuel line to carb and route fuel supply to pump. Much easier than fighting all the other problems we kept running into. We'll keep everyone posted on how it goes. And yes, we're going to install a new oil pressure switch, however we did already install a mechanical gauge. At least this way the factory dash work hopefully work correctly.
Thanks, David
1970 CST LB Fleetside, 402 BB, PS, PB,AC
1968 Firebird 400 conv.
1965 Chris Craft 17' wood ski boat (SN #0001)
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Old 06-15-2018, 12:32 PM   #27
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Re: '89 K1500 engine replacement help

Why not just wire in a new fuel pump relay that isn't triggered by the ECM?
1988 Chevrolet C1500 RCSB
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Old 06-21-2018, 05:20 PM   #28
68 TT
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Join Date: Jul 2009
Location: Spokane, WA
Posts: 3,442
Re: '89 K1500 engine replacement help

The stock TBI fuel pump is not capable of flowing enough fuel to feed even a 300 hp engine without it going dangerously lean let alone a 400 hp one.

Replace the stock TBI fuel pump with a high volume in-tank pump with a flow rate of at least 255-LPH or an external mechanical fuel pump and a bypass style fuel pressure regulator returning the excess fuel to the tank using the stock TBI system return line.
67 C10 Suburban The Ant Farm
69 C10 shortbed stepside project 45 ACP
69 K20 lwb TBI 400 4L60E NP208 square body chassis
68 Camaro SS / RS 500hp 439 inch big block T-400
79 Malibu TPI 350 4L60 3.73 gears
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Old 06-21-2018, 08:21 PM   #29
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Re: '89 K1500 engine replacement help

My stock replacement pump fueled the 406 in my old truck. Didn't run lean, pulled like a train on steroids....
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